Apparatus for making die castings



Aug. l8, 1942.

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defective in a number of ways.

tion to enter and -by introducing the' tively low velocity at the point of junction bel the mold at high velocity,

Patented Ate. 1a, 1942 UNITED STATE s PATENT OFFICE.

APPARATUS roa MAKING um cssrmas wuum rum. Detroit, Mich. Ap lication September 10. 1936, Serial No. 100,154

1 Claim. (o1. 22-68) This invention relates toa process and apparatus for making die object to provide a new and improved'apparatus o this description. a

Heretoi'ore, die castings had gases entrapped in the metal so that they were porous and therefore This porous feature, ,ior example, reduces the strength of the casting and where the casting is plated, the porous sections tend to permit the plating solu discolor the surface. when the castings are devices which rotate and should therefore necessarily be balanced, the porosity tends to bring about an unbalanced condition in the rotating part. The invention has as a further object to provide a process and apparatus by "means'oi which die castings are made without porosity.

In carrying the invention into practice, the metal is introduced into the mold without the admission of air or other gases and in such a manner as to permit any air that should be in the mold, to escape. This result is accomplished metal into the mold at relatween the mold and the nozzle through which the metal passes. This introduction the metal into the mold by a comparatively low velocity prevents the drawing in of air which would otherwise get into the mold and cause porosity of the casting. It also permits the use of the mold at a' lower temperature so that none of the components of the metal are converted into gas to cause porosity of the casting, as is the case where the metal is introduced at a higher temperature. Furthermore, when the metal is introduced into this high velocity reduces the pressure and thereby lowers the boiling point of the molten metal, which tends to cause some component parts of themetal to vaporize, thereby causing porosity of the casting.

The invention has as a further object to eliminate the danger oi. iniury to users of the apparatue. The invention has as a further object to provide a process and apparatus of this description by means of which the molten metal cannot be supplied until the receive it. The invention has as a further object toprovide a process and apparatus of this description wherein the die may be moved into proper positionwithout the use of the hand or other part of the person oi the operator. The invention has as a further object to provide a process and apparatus of this description by castings and has for itsdie is in proper position to a system shown toiore can be produced and which increases the density of the casting and insure the elimination of objectionable porosity, so as to produce a fine, dense, homogeneous, balanced and strong cast- The invention has as a further object to pro-' vide a device of the kind described, by means 0! which the molten metal is inserted in the mold by at least two steps, the first step consisting in. bringing the charge of molten metal in proximity to the mold by one means, inserting it into the mold by another means. The invention has as a further object to provide-a device of the kind described, wherein the charge of molten metal is moved into a molding cavity in proximity to the mold and is then forced from the molding cavity into the mold. The invention has other objects which are more particularly pointed out in the accompanying description.

Referring now to the drawings, wherein I have illustrated one form of device embodying the invention, Fig. 1 is a side elevation of a die casting machine, showing the pit underneath;

Fig. 2 is an enlarged longitudinal section of the left-hand portion of Fig. 1;

Fig. 3 is a section similar to Fig. 2,- showing the right-hand portion of the device of Fig. 1; Fig. 4 is. a plan view of the portion of the device shown in Fig. 2, with parts in section along the line 4-4 otFig. and piston link omitted for Fig. 5 is a sectional view of Fig. 1;

Fig. 6 is a sectional view along the line 6--6 of Fig. 1, showing the die;

clearness;

along the line 5-5 Fig. 7 is a diagrammatic view showing the oil circuit and valve system, with certainbt the parts in section to more fully illustrate their operation;

Fig. 8 is a detail, in part section, of the starting .valve;

Fig. 9 is a diagrammatic view of a part 01 the in Fig. 'l, but on a larger scale; Fig. 10 is a detailed section along the line Ill-I001 Figs. 9 and 11; Fig. 11 is a sectionalll--ll of Fig. 10; I

Fig. 12 is a section similar to Fig. 11, oi the view taken on the line v pilot valve operated by the movement of the plunger which moves the charge of .metal into the means of which a much better casting than heremold; and

Fig. 13 is a time diagram showing one arrangemerit of time allowed for each operation. by

and then 1 with the cylinder support means of which satisfactory results can be prothe several figures.

Referring now to the drawings, I have shown 5 one form of die casting apparatus and one form of automatic operating mechanism therefor.

Referring now more particularly to the die casting apparatus, this apparatus consist of a mold in which the material is cast. This mold as hereinshown consists of two sections I, and 2. One of these sections is movable, as for example, the section I. This section may be moved in any desired manner. The section 2 is preferably stationary and is supported in any desired manner. In the construction shown the section 2 is connected by the members 3 with the support 4.

' When the sections are brought together, there is formed a metal receiving chamber 5. The member 2 of the mold is provided with a passageway 6 into which the molten metal is introduced. This passageway has a connecting passageway l which connects with the metal receiving chamber 5 of the mold. The metal is introduced into the mold, that is the passageway 6, by means of a nozzle 8. This nozzle is comparatively large, that is it has a comparatively large cross-sectional area, being considerably larger than the nozzles now used in introducing, the molten metal to the mold.

The molten metal is introduced into the nozzle 8 in any desired manner. I have illustrated a particular and efiicient manner of introducing this metal into the nozzle. In this construction I provide a pot 9 containing molten metal. This pot is heated in any desired manner. For the purposes of illustration, I have shown the pot as being heated by the burners I 0. When gas is used for the burners, I may provide a blower ll into which the gas is introduced through the pipe l2. Air is also introduced into the blower through the opening l3 and mixed with the gas and this mixture is directed by the pipe H to the burners iii. The blower may be operated by a motor I 5.

Associated with the pot 9 is a measuring device, which is illustrated as a ladle l8 pivotally mounted at IT, preferably to the'supports 4a. This ladle is provided with a drain member I! which extends through the bottom thereof andv which is provided with a passageway l 9 extending therethrough. The ladle is moved down into the pot of molten metal, as illustrated in full lines in Fig. 2, and is then moved up to a position as shown in dotted lines in Fig. 2. Any surplus of molten metal in the ladle" runs out through the opening l9 and when the ladle is moved to its discharge position, as shown in dotted lines in Fig. 2, it always contains the same amount of molten metal, so that the charge of molten metal for the mold is always the same. If it is desired to vary the amount of metal introduced into the mold, it is only necessary to vary the height of the drain member I 8. When the ladle ismoved to its discharge position, the molten metal is discharged through the opening 20 into a conducting member 2| which communicates with the interior of the nozzle 8, so asto discharge the molten metal into such nozzle. The pot and associated parts are preferably removably mounted in a heat chamber 9a.

Some means is provided for moving the molten metal into the metal receiving chamber 5 of the mold. In. the construction illustrated I provide a plunger 22 which moves along the passageway 23 in thenozzle and the passageway 6 in the sec- 7 tion 2 of the mold. This plunger may be moved in any desired manner and when the charge of metal is introduced into the passageway 23 of the nozzle 8, the plunger is moved forward past the discharge opening 24 and forces the molten metal into the metal receiving chamber 5 of the mold.

The metal is introduced into the mold without the admission of air or other gases and at the same time, permitting the air in the mold to escape. In the device herein illustrated, this is accomplished by introducing the metal into the mold at relatively low velocity at the point of Junction between the mold and the nozzle. The reason why the metal can be introduced at this relatively low velocity is because it is introduced into the mold through a larger opening than can now be used. It will be noted that the nozzle 8 has a comparatively large passageway and that it connects with the comparatively large passageway in the section 2 of the mold and that the metal passes from the comparatively large passageway 6 in the mold section 2 through a comparatively small connecting passageway I leading to the metal receiving chamber 5. The air in the mold after the metal is introduced therein, escapes through thevent or vents 25. The introduction of the metal into the mold at a comparatively low velocity prevents the drawing in of air with the metal introduced into the mold. It also permits the use of the metal at a lower temperature, as for example from 735 F. to 775 F., whereas heretofore the temperature had to be above 800 F. This lowtemperature at which the metal is introduced into the mold is of great importance because at this lower temperature, none of the components of the metal are converted into gas, whereas at the higher temperatures heretofore used, some of these components are converted into gas and this gets into the metal in the mold and makes it porous. Furthermore, when the metal is introduced into the mold at high velocity, as has heretofore been the practice, this high velocity reduces the pressure and this lowers the boiling point of the molten metal. and the lowering of the boiling point of the molten metal causes some of the. component parts of the metal to vaporize, thus forming gas which gets into the mold and makes the casting porous. Another advantage of introucing the molten metal into the mold at a comparatively low velocity is that this prevents turbulence in the mold, thereby preventing the vent from being closed. This insures the escape of all the air in the mold so that there will be no air caught in the molten metal to make it porous.

After the mold is substantially filled with the molten metal under the pressure used in forcing the metal into the metal receiving chamber 5 and when the chamber is substantially filled with metal, increased pressure is applied to the molten metal in the mold as afinal step in this part of the process. This final increased pressure on the metal is preferably brought about Just as the.

pressure on the metal in 4 After the metal in the mold has solidified,

, member I. After the member I has provide a large cylinder guide screws 4 la.

mold is provided with a core 2i,'this core being attached to the movable section I of the mold. the two members of the'mold are operated and the casting removed. In the construction illustrated, the member I of the member 2 and the casting moves with the been moved a sufllcient distance the push members2'l are held against movement and they push the cast.--

ing from the mold section I, so as to release it.

As previously stated, the die casting mechaworks in a cylinder 46 which isprovided with a stuffing box 46a. The piston 45 is connected the mold is moved away from nism as herein described may be operated in any I desired manner, by any desired mechanism. I prefer to provide automatic means for operating it and I have illustrated in the drawings such automatic means, the apparatus being automa tically operated hydrostatically. In this operation,there is a control valve which is operated. and the operation of this control valve causes the apparatus to automatically :0 through the cycle of operation as follows;

, The section I of the mold is moved into op- I erative relation with the stationary section 2 of the .mold. The ladle I6 is then moved to introduce a charge of molten metal into the nozzle passageway 23. The plunger 22 is then moved to force the molten metal into the mold under a predetermined pressure and then after the mold is substantially full, the "pressure with which the plunger 22 acts upon the molten metal is increased so as to give a final high pressure squeeze to the metal in the mold. The section I of the mold is then moved away from the member 2 and the casting pushed from the section I. the

action being properly timed so that all the parts work in proper relation to each other to produce the casting. I

In carrying out this automatic operation I 28 having a piston 23 to which is connected the piston rod 30 of,a

small piston 3I which works in a smaller cylinder 32. The piston 30 passes through a stuillng box 33.. There is also connected with the large piston 29 a plurality of rods 34 which pass through stufilng boxes 35 and which are connected to a movable member 36. These rods pass through openings in a guide member 34a. This movable member is preferably provided with friction reducing means, such as one or more wheels or rollers 31 working upon the track 33. Attached to the member 36 is a mold section supporting member 39 which supports the mold section I in any desired manner. as by means of the threaded supporting members 40. This mold section supporting member is provided at,

The plunger 22 which forces the molten metal into the mold is connected with a piston 45 which by a piston rod 41 with a larger piston 48 which works in a cylinder 49 which is larger than the cylinder 46. The piston rod 41 works in a stuffing box 4111. In the operation of the device, the increased pressure on the molten metal in the mold after the metal receiving. chamber 5 is substantially filled, is brought about by means of this large piston '43. This produces an increased pressure on the mold section I and this increased pressure is opposed by the large piston 29 in the large cylinder 23.

The ladle I6 is operated by means of a cylinder 50 and a piston 5i which is connected to the ladle by a piston rod 52.

These various pistons may desired manner.

be operated in any I have shown one method whereby they are automatically and hydrostati provide pipe connections and the valves are duplicated,

one set of pipe connections and valves being for operating the mechanism which controls the its end near the'section I of the mold with a vertically extending slot into which is received the member 4| with which the push members 21 are connected. The member H is guided on the In the construction shown, the push members are directly connected to the piece 42 and this piece is removably connected to the member 4|. Connected with the member 4I' is an actuating member 43 for the push members 21, which slides in openings in the members 3 and 39 as the mold section I is moved away from the mold section 2 and which strikes the stop 44 during this movement. This stops the movement of the member 4i and the push members 21 and produces a relative movement between the push members 21 andthe mold section I, which pushes the casting from the mold section. This is all done automatically as will be hereinafter described.

mold and the other for operating the mechanism which introduces the metal into the mold. I have shown diagrammatically the system of pipes and control valves in Figs. '1 and 9. For securing pressure and moving'the liquid through the pipes,.I provide the pumps 54 and 5 5 operated by the motor 56. Pipes 51 and 58 lead from the pumps into the tank 53 containing the liquid.

Connected in the system is a main control valve A. The system is also provided with two similar relief valves B and B. similar four-way valves D and D There are two similar bypass valves E and E. There are two similar check-way valves F and F. There passing through them supplies the power to operate the mold and ladle. In describing these pipes, I will describe one set of pipes applying numerals thereto, and the duplicate set of pipes will be provided with the same numerals, with an exponent. I

Referring now to the powerpipes, the pipe 60 connects pump 55 with the relief valve B. The relief valve B is connected by pipe GI with the four-way valve D. A pipe 62 connects the fourway valve D with the cylinder 32 which moves section I of the mold. A pipe 53 connects cylinder 32 with pipe 64 which connects with the fourway valve D. The pipe 64 is connected to a pipe 35 'which connects with the bypass valve E. A pipe 66 connects four-way valve D with a pipe 61, which connects with the relief valve B and the pipe 68 leading to the tank 53. A pipe 69 connected with the pipe 61 connects with one end of the cylinder 28. A pipe Ill connects the pipe 89' with the check-valveF. A pipe II connects the liquid by means of There are two.

the checkvalve F with thecylinder a at the opposite end thereof and a pipe 12 connects this same end of cylinder 28 with the bypass valve E. A pipe 13 connects the pipe 12 with the ladle control valve J and a pipe I c n s e l dl control valve J with the ladle actuating cylinder 50 on one side of the piston and a pipe 15 connects the cylinder 50 onthe other side of the piston with the pipe 62. The duplicate power pipes are given the same reference numerals with the exponent a."

The bypass valve E has a valve member which is pressed to its'seat by an adjustable spring and controls the communication between pipes 66 and 12.

I have shown the power and control pipes diagrammatically in Fig. 'I, but it is of course evident that these pipes may be arranged-in any desired manner and they are shown diagrammatically in Fig. 7 so that they may be easily designated and followed. For example, in Fig. 7, the pipe. 62 is connected with the cylinder 32 at the side thereof. In Fig. 3 I have shown this pipe 62- as being connected to the cylinder 32 at the end thereof. The point of connection is simply a matter of convenience and will be dependent upon the conditions presented.

Referring now to the control pipes, the relief valve B has connected therewith the pim 15 which connects with the check valve 11, the check valve being connected with pipe 18 which connects with the control valve A. This control valve has a casing 19 with which the various control pipes connect and within the casing is a hollow rotatable control member to which is connected a control handle 80b. This control member has a port 8| which, when the handle 80b is moved in the proper direction, connects with the pip 18. The control member has another port 82 which connects with th pipe 86. .The control member has another port 88. This port 8 3 has a laterally or circumferentially extending portion 85, so that the port 84 may be connected either with the pipe 18 or the pipe 83. I prefer to provide a construction as herein shown where the control member 00 is hollow and the ports connected therewith, so that the pipes need not be in the same horizontal plane. The port 64 connects with the pipe 06, which in turn is connected by the pipe 61 with the four-way valve D. This four-way valve is provided with three united pistons, 88, 89 and 90 which control the Power pipes connected with the valve. When the valve is in'the position shovin in Fig. 7, the power pipes 6| and 62 are in communication and the power pipes 64 and 66 are in communication. When liquid is admitted through the pipe 81, the pistons are moved toward the other end of the valve and the pipes GI and 64- are in communication and the pipes 62 and 66 are in communication. The pipe 66 connects with the timing valve 0 which is illustrated in section in Fig. 9. This timing valve has a piston provided with two grooves 9i and 92. This piston is moved inwardly by the member '63, connected in any desired manner so as to move with the pistons 29 and 3|, as by means of one of the rods 34. As the member 93 moves to'the left, it engages the roller 95 and moves the piston inwardly so as to bring pipes 06 and 81 into communication. The piston is moved outwardly by the spring 66 when the roller 95 is released by the member 93. The timing valve 0 is provided with a passageway 88, which when the piston is released by the member 03,- connects with the groove 62 and by means or the slot 02 with the pipe 06. The cates with the pipe I02.

The pipe 91 connects with the passageway III in the relief valve B. A valve member I03 closes, I00 and is normally the end of the passageway held in its closed position by I01 in a chamber I05. The nected by a passageway I06 with a chamber I01. Within the chamber I01 is a valve member I06 which is pressed by a spring I00 against its seat to close th pipe 61. The pipes 60 and 6I are alwaysin communication. When the pressure in the valve chamber becomes suflicient, the valve chamber is opened by the pressure on the enlargement I M, so that pipe 61 communicates with pipes 60 and Eli. The pressure of the liquid entering the chamber I06 from pipe 91, when suflicient, acts upon the valve I08 so as to close it again.

y A pipe H9 leads from power pipe 62 to the end of the check-way valve F which is proan adjustable sprins chamber I05 is convided with a piston Iii to which is attached a piston III from that liquid from this pipe ent valve member H2, adapted to control the port 8 and thus control the connection of pipe 10.

to the cylinder 28. When liquid enters the valve F through pipe Ili'i, it moves the piston to open valve member IIZ. A pipe He is connected with the check-way valve F on the other side of the of the pipe I I 0 and when e rs the valve F, it moves the piston III to close the valve member H2. A pipe H5 leads from pipe I 0' which is provided with a piston, see Fig. 9, having the grooves IIB ton is in the position shown in the drawings,

- the groove H6 connects the pipes H6 and H9.

Pipe H8 connects with the end of the four-way When the piston is pressed down as hereinafter set out, the groove 1 communicateswith the passageway I20, which communicates with the pipe '5 and through the agency oi the slot I2I communication is made between the pipes H5 and II8.- The piston is returned to its initial position by means of spring I22. The pipe 6 connects with the time delay valve M preferably by being connected with the pipe I 23 which connects with a passageway I26, which leads through a spring-pressed valve member I25 to the interior of the time delay valve M at one end of the piston I26, held in its initial position by the spring I6I. The passageway I24 communicates with the passageway I21, which in turn communicates with the passageway I28 leading into the time delay valve M at the same end of the piston I26 as the passageway I24. There is an adjustable valve member I26 which controls the connection between the pasasgeways I21 and I26. The piston I26 is provided with an elongated groove I20. When the piston is in its initial position, as shown in Fig. 9, the pipe IJI leading to the fourway valve D' in the duplicate set of pipes, is brought into communication by the groove I20. with the pipe I22 which leads to the pilot valve N. A second passageway controlled by spring-pressed valve I60 connects pipe I2I with the groove I20. The pipe I23 also leads to this pilot valve and there are pipes I32 and I connected with the pilot valve N. This pilot valve N is controlled by the ladle controlling piston and cylinder 60 I with a rotatable control member I26, see Figs. 10 and 11. When the member I26 is in the position shown in Fig. 11, pipes I23 and I are in communication and pipes I32 and I are in valve D.

in the piston, connects passageway 66 communino: to the timing valve and 1. When the pis- I and II and is provided the movement of the I the members I39 communication. when the control member I35 is moved a proper distance, these pipes are disconnected and the pipe I33 is connected with the pipe I32 by means of the passageways I39, N" and N and the pipe .I23 is connected with the pipe I34 and N. This control member I35 is rotated by piston rod 92 which carries and I49 which engage the members HI and I42 attached to the control member I35. The pipe I34 leads to the tank 93. The pipe I33 connects with the pipe I43 which connects at one end with pipe 19 leading to the control valve A, and at the other end with the,

pilot valve N. This pilot valve N is similar to the pilot valve and N I have applied the same reference numerals thereto with the exponent a. From the pilot valve N pipes I32a and I23a lead to the time delay valve M and pipe I34d leads to pipe I34 and thence to the tank 93. A pipe I44 connects the time delay valve M with the end of the four-way valve D. The time delay valve M is similar to the time delay valve M and I have applied'similar reference numerals thereto with the exponent a.

The pilot valve N is similar to the pilot valve N and is operated in a similar manner by a member I45 connected with the pistons 45- and 49 which are used to introduce the charge of metal into the mold. This member is provided with actuating parts I49 and I41 which successively engagethe members I49 and I49 connected with the rotatingpart of the pilot valve. The members I49 and I49 are in diiferent vertical planes so that neither of the members I41 and I49 will strike parts are in the position shown.in Figs. 7, 9 and 12, the pipe I32a. is connected with the pipe I34a and the pipe I23a is connected with the pipe I43, see Fig. 12. When the engaging member I49 engages the member I49, so as to move the rotating valve member, this member is so moved that the port I59 will connect pipes I-32a and :4: and the port I5I will connect pipes I34a and 2 a. 7

As before stated, with. this apparatus the action of the parts is automatic through the entire cycle. In Fig. 13 I have illustrated a diagram showing the cycle of operations when the particular automatic apparatus herein shown is used. It is or course evident that other automatic apparatus might be substituted and that this apparatus might} be modified and changed in manyparticulars. This diagram is simply for the purpose of giving a quick visual representation of the cycle of operation and the time occupied for the different steps in this cycle of operation. In this diagram, for example, the time of starting to close the mold is represented at the top by the word"Start. period for the mold in the particular apparatus herein shown is 18.5% of the entire cycle. The dumping period, that is the period used in dumping the metal from the ladle, is 9.2%. The precasting dwell, that is the pause between the dumping and casting, is 18.5%. -The casting period is 9.2%. The period occupied by the. final step, that is the increasing pressure on the molten metal in the casting at the end, is 1.1%. The post casting dwell when the mold is held closed and the metal cooling, is 25.0% and the knockout of the-casting and thereturn-of'the "mold section to its open position is 18.5%.

I will now describe the operation of the automatic hydrostatic operating mechanism for the by means of the passageways I31, N

The closing parts their retracted positions,

and will begin this description when the mold controlling pistons and mechanism and the mold charging pistons and mechanism are in the mold controlling pistons 3I and 29 being in the right end of their cylinders and the mold charging pistons 45 and 49 being inthe left end of their cylinders. The

. motor 99 is started. which in turn starts pumps 94 and 55. The'lever on control valve A is then shifted in the direction of the dart or arrow, thereby connecting pipes 19 and 99, see Figs. 7 and 8. Liquid pressure is then directed from pipes 9| and 19 of relief valve 3 to the following,

from port 19 through pipe 19, control valve A and both of them. When the pipe 99 to pipe 91 connecting with four-way valve D, moving the valve piston to connect pipes 9I and 94. The liquid pressure is then directed from pipe 9I through valve D to pipe 94 and pipe 93 and into the cylinder at the right of piston 3I and'also through pipe 95 to bypass valve E. Liquid pressure is then directed from pipe 19 through pipe I43 to pilot valve N and then through pipe I23a to time delay'valve M, shifting valve piston to close pipe I32a. Liquid pressure is then direct- 'ed from pipe 19 through pipe I43 and pipe I33 through pilot valve N, then through pipe I23 to valve M, shifting valve piston to close pipe I32. The liquid then passes through pipe I I9, through timing .valve 0', and then through pipe II9 to four-way valve D, shifting valve piston to connect pipes 9Ia and 92a, to direct liquid pressure into cylinder 49. This returns pistons 45 and 49 to their starting positions to insert the charge into the mold.. The shifting of both valves M and M is delayed by check valves and I25a and IBM, as clearly shown in Fig. 9.

The liquid from pipe 93 entering die cylinder 32, moves die pistons 3I and 29 to the left, which causes the liquid in front of the'piston 29 to pass through pipes 99 and 19, check-way valve F and pipe 1I into cylinder 29 back of piston 29. At the same time, liquid is being returned to tank 53 from die cylinder 32 through pipe 92, bypass valve D and pipes 99, 91 and 99. Liquid is also being returned through valve D pipes 99, 91 and 99 leading to tank 53 through pipe I44, time delay valve M, pipe I32a,'pipes 'I34a and I92a, the check-valve in valve M delaying the shift of the valve piston to allow return liquid to pass through pipes I32a and I44. Liquid pressure from pump 55 and through pipes 99 and 9|, valve D and pipe 94 passes through bypass valve E and through pipe 12 tocylinder 29. Liquid pressure also passes through pipe II4 under piston III, closing valve member II2 of check-way valve F. The die piston has now completed its leftward motion to close the die and is under pressure awaiting the function of dumping the metal from the ladle. When in this position, the member 93 engages the members I52 and I53 of valves and 14 with the ladle controlling cylinder 59 and the piston 5|, moving the piston rod 52 attached to the ladle I9, to move the ladle and discharge molten metal into the nozzle 9, see Fig. 2. Near the end of the upward stroke, actuating member I49 shifts lever I on valve N, which directs liquid pressure thrcugh pipe l33, valve N andpipe I32 to valve M, see Figs. 7, 9 and 19. Liquid is now being returned to the tank 53 through pipes I23, valve N and pipe I34. After all the liquid I25 and I99,

has been drained, pipes I32 and Iii connected with valve M are connected, carrying the liquid pressure to the end of four-way valve D'. Ladle controlling piston remains in its upward position.

The liquid pressure from pipe I3I shifts the valve member of four-way valve D' to the right and directs liquid pressure from pump 54 through pipe 5Ia, pipe 64a and pipe 53a into cylinder 48. Liquid pressure is also directed through pipe 65a to valve E. The pistons 45 and 48 are now moving to the right, caused by the liquid entering by the pipe 63a. At the same time, movement of piston 48; causes liquid to be drawn from cylinder 49 in front of the piston through pipe Ila, valve F and pipe Ila into the cylinder 49 back of the piston 48. Additional liquid is being drawn from the tank 52 through pipes 69a and 67a, to completely fill the cylinder 49. The movement of these pistons to the right disengages the member I54 of valve 0 and its piston moves upwardly, see Fig. 9, thereby disconnecting the pipe I55 leading to pipe 654: and pipe I55 leading to check-valve B. Liquid is also now being returned from cylinder 46 through pipe 52a through the valve D', pipe 86a, pipe 61a to the left. Liquid passes and pipe 68a to the tank 53.- Liquid from pipes 54a and 65a passes through bypass valve E and then through pipe 12a into the cylinder 49 at the left of piston 40. Liquid also passes from pipe 12a through pipe II la into valve F below piston I I la, closing valve member 2a. The' mold charging pistons 45 and 48 have now completed their motion to the right and the plunger 22 has moved the charge of molten metal from the nozzle 23 into the mold, see Fig. 2.

Just before the dwelling point of pistons 55 and 48, engaging member I45 shifts member I 49 on pilot valve N', thereby directing liquid through pipe I43, valve N and pipe I32a to valve M. At the same time, liquid is being returned from valve M' through pipe I23a, valve N, pipe I340: and pipe I02a to the tank. After all the liquid has been drained from valve M, pipes I32a and I44 connecting with valve M are connected, directing liquid pressure into the D. This shifts the piston of this valve to the right. This connects pipes GI and 52, directing liquid from the pump 55 into the die cylinder 82, starting the return motion of the die pistons. Liquid passes through pipe I III into valve F above piston III, moving it to open the valve member 2. The movement to the right of piston 3i moves member 93 to release member I53 of valve J and this disconnects pipes 13 and I4, see Fig. 9. This movement also releases the member I52 of valve 0' and this connects pipes Ill and H9. Also liquid passes from pipe 52 through pipe 15 to ladle controlling cylinder 50 which starts the Piston 5| on its return movement to move the ladle back into the pot 9. The liquid returns to the tank" from the cylinder 50 by passing through pipe I4 and passageway 14b in valve J and check valve 14c and passageway 14d. Liquid is being returned to the die cylinder 28 to the left of piston 25 through pipe II, valve F and pipe III and a portion oi this liquid is returned to the tank 52 through pipes 59, 51 and 65. .Liquid is also returned to the tank from the die cylinder 22 through pipes 53 and 54, valve D and pipes 55, 41 and 68. Liquid returns to the tank 52 from valve D through pipes 81, 55, control valve A, pipes 83 and I02. At the end of the retumstroke of die pistons 3| and 29, member end of four-way valve as on valve 0' so as to move the cylinder of this valve and connect pipe II to pipe 51 leading to relief valve B. Inasmuch as relief valve 13 has been vented through valve 0 the pilot pressure necessary to return valves M and M' comes from relief valve B through pipes Ila, I45 and I32 to valves M and M. The return of mold charging pistons 45 and 45 starts Just before the complezioon of the return stroke of ladle controlling pis- Engaging memberv I39 shifts member I42 on valve N, moving said valve to connect pipes I24 and I33, directing liquid from pipe in into the passageway I 24 of valve M, resetting the time delay valve M: The liquid also passes through pipe IIO, valve 0' and pipe II8 to the end of valve D. This liquid shifts the piston of valve D' connecting pipes Ma and 52a, permitting the liquid from the pump 54 to enter the die charging cylinder 45 and cause the piston 45 to move through pipe Ilia from pipe 52a into the valve 1- above piston Ia and moves this piston to open valve H211. Liquid is now being returned to the tank 53 from cylinder 46 through .pipes 52a, 54a, valve D, pipes Slim-"51a, and 68a. Liquid is also returned from valve D, when the piston moves to the left, to the tank 53 through pipe III, valve M, pipe I22, valve N, pipe I34 and pipe I02a.

Liquid from cylinder lIa, valve F and pipe 10a to the cylinder 49 on the other side of the piston 48 and the excess liquid passes through pipe 69a, pipe 61a and pipe 68a back to the tank 53. Near the end of the return stroke of die charging piston 45, member Ill? on member I45, connected therewith, shifts the member I48 of valve N connecting pipes I43 and I23, and the liquid passing from pipe I22 to the delay valve M moves its piston to reset it. At the end of the return stroke of the mold charging pistons, the member I45 engages the member I54 of valve 0 so as to move said valve to its open position, connecting pipes I56 and I55, venting relief valve B. In the meantime, the connection between pipes 91 and I02 through valve 0 has been closed. Also the control handle 80b on control valve A has returned to its former position by means of the pressure of the liquid or by means of the spring 800, see Fig. 7.

It will be noted that in this process and apparatus the molten metal in measured quantities is placed in proximity to the mold by gravity and it is not until it is in position and substantially at rest, that pressure is applied to the molten metal to force it into the forming device or mold. It will further be seen that this molten metal is brought into proximity to the mold without being under pressure and comes to rest without being under pressure and that then the pressure to force it into the forming device is applied to it. It will also be noted that molten metal is received in a portion of the 3 mold or forming device before pressure is applied to it, to force it into the metal receiving chamber which shapes it. There completely filled with molten metal by gravity.

Furthermore, this nozzle and passageway in the forming device are both completely filled with the molten metal before the pressure which forces the metal into the metal receiving cham- 53 connected with said pistons, engages member bet is applied. In this construction the molten metal is moved first in a generally vertical di- 49 passes through pipe chance to escape, and substantially no automatic mechanism.

rection, and by this I mean a direction sufliciently so that by related to the vertical that gravity will move the metal, and then in a generally horizontal direction to bring it into position to be forced into the molding cavity of the mold. When the measured charge is used, so as to completely fill the nozzle and-the communicating passageway in the mold, this metal is traveling at a comparatively slow speedjand fills the nozzle and this passageway from the bottom 'up, thus giving the.air a air is entrapped in the'nozzle and in the passageway of 1 the mold in alignment therewith.

The moltenmetal after being deposited in the nozzle and the passageway in the mold, comes to rest before pressure is applied to it andthis insures the escape of all entrapped gases and at the same time insures the easy, steady, flow'without turbulencaof the molten metal into the molding cavity of the forming device so that there will be no splashing or agitation which would cause the molten metal to partially or wholly close the vent through which the air in the metal receiving cavity is discharged. It will thus be seen that under these conditions when the pressure is applied to the molten metal, this molten metal, tree from air, is forced into the metal receiving chamber where it is shaped, free from air or other gases, so as to be free from porosity.

When the automatic mechanism is used for operating the device, the various valves and constructions are arranged so as to provide the proper delays at the proper points without the intervention of any mechanism other than the This permits the precasting dwell of the desired length while the molten metal is in the nozzle and the enlarged passageway in the mold, which is an important factor, and it also permits the post-casting dwell, that is, a suihcient delay. after the metal has been forced into the mold to permit the metal to cool ated means for moving said plunger to force the the next action of the apparatus the mold members are separated and the casting removed therefrom. ,7

In this device it will be noted that there isra' charging chamber wherein the charge of molten metal for the mold is received, the charge of metal displacing the air from the charging chamber, the charge coming substantially to a stop in this charging chamber, and then the pressure device is applied to the charge, so as to" move it into the mold free of entrapped gases.

I claim:

An apparatus for forming die castings comprising a formingdevice, means for forming the molten metal into a measured quantity, a horizontally extending cylindrical member into which said measured quantity is received and which brings the molten metal a complete cylinder, a plunger engaging the end of said cylinder of molten metal, a power actucylinder of molten metal toward the forming device without changing its cross sectional area until 'it reaches the forming device, means associated with the forming device for changing the direction of the molten metal as it enters the forming device, into a vertical direction,'said power actuated means slowing up the movement of the molten metal, to cause it to enter the forming device free of turbulence and move the air in the forming device before it without mixing with this air, an air escape device at the topmost portion of the forming device through which the air escapes so that the forming device is completely filled with molten metal, and anadditional power actuated means for applying increasedpressure to said plunger to cause it to apply additional pressure to said molten metal after the forming device is completely filled therewith.

to rest and forms it into, 

